JP2005249426A - Casting inside flaw inspection support device and inspection support method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a casting inside a flaw inspection support device, capable of inspecting a casting simulated result, with respect to a casting product to be inspected and capable of enhancing the estimation precision of casting simulation, and to provide an inspection support method which uses it. <P>SOLUTION: The casting inside flaw inspection support device is equipped with an actually measured model-forming means for receiving the cross-sectional images of a plurality of the cross sections of the cast product to be inspected, formed by actually measuring the casting product to be inspected and forming the three-dimensional shape model of the casting product to be inspected, a flaw discriminating means for discriminating the part corresponding to a hollow cavity in the casting product to be inspected from the three-dimensional shape model formed by the actually measured model-forming means as a hollow cavity model, and a hollow cavity volume ratio calculating means for providing divided regions to the cavity model discriminated by the flaw discrimination means and calculating the hollow cavity volume ratio at each divided region. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a technique for supporting inspection of internal defects such as a cast hole formed in a cast product.

  Among the defects that appear in the casting, there are defects that appear inside the product, such as a casting hole such as a shrinkage cavity. Such defects, such as a casting hole, can adversely affect performance such as the strength of a cast product, and thus are not uncommon. However, as a practical problem, it is extremely difficult to eliminate the cast hole. Therefore, by adjusting the product shape and the casting method, it is possible to cast in parts that have little effect on performance (for example, parts to be removed in a later machining process). A method of concentrating the nest is used. In this case, at the stage of design for production, the prototype and inspection are repeated while changing the shape and casting conditions in various ways to search for the optimum conditions.

  Here, in the inspection of internal defects, it was necessary to destroy the product itself. Such a destructive inspection requires labor and time, and is not very high in accuracy. Further, the work used for the destructive inspection cannot be subjected to a test for the entire work such as a strength test thereafter. was there.

On the other hand, in recent years, nondestructive inspection using X-rays is often used. Particularly recently, a system has been proposed that visually presents the state of internal defects by imaging a cross-section inside a cast product by X-ray CT (computer tomography) (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 11-296700

  The inspection using the X-ray CT has an advantage that it is easy to visually confirm the presence or absence and position of an internal defect because a tomographic image to be inspected is obtained.

  However, with these conventional techniques, it is possible to know the presence or distribution of the internal defects of the measured casting, but it is not possible to quantitatively know the volume distribution of the internal defects. Therefore, even if the volume distribution of internal defects is predicted by casting simulation, there is no indication of how reliable the obtained result is, so there is some information based on information about internal defects obtained from castings. Even if countermeasures (for example, changing casting conditions) are taken, it is difficult to accurately confirm the effect.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a casting internal defect inspection support apparatus and method capable of verifying the casting simulation result and improving the prediction accuracy of the casting simulation. .

  The casting internal defect inspection support device of the present invention receives cross-sectional images of a plurality of cross-sections of the cast product formed by actually measuring a cast product to be inspected, and based on the tomographic images of the plurality of cross-sections, Measured model forming means for forming a three-dimensional shape model, defect identifying means for identifying a portion corresponding to a cavity in the casting as a cavity model from the three-dimensional shape model formed by the measured model forming means, and the defect identification And a cavity volume ratio calculating means for providing a divided area in the cavity model identified by the means and calculating a cavity volume ratio for each of the divided areas.

  In a preferred aspect of the present invention, the actual measurement model forming unit forms a surface model of the cast product as the three-dimensional shape model, and the defect identifying unit configures an outer surface of the cast product in the surface model. Identifying a portion corresponding to the cavity by identifying a surface element group to be performed and identifying a surface element other than the surface elements constituting the outer surface as a surface element surrounding the cavity, and the cavity volume ratio calculating means includes: A plurality of points are plotted for each of the divided regions, a point existing in the cavity in the divided region is determined from the plurality of points, and it is determined that the points are present in the cavity with respect to the total number of points plotted in the divided region. It is desirable to calculate the ratio of the number of points as a volume ratio.

  Further, the cast internal defect inspection support device of the present invention receives cross-sectional images of a plurality of cross sections of the cast product formed by actually measuring a cast product to be inspected, and based on the tomographic images of the cross sections, the casting An actual measurement model forming means for forming a three-dimensional shape model of the product, a defect identification means for identifying a portion corresponding to a cavity in the cast product as a hollow model from the three-dimensional shape model formed by the actual measurement model forming means, The cavity model identified by the defect identifying means is provided with a divided region, and the cavity volume ratio calculating means for calculating the cavity volume ratio for each divided region, the shape information of the cast product, and the casting performance of the cast product or the correction Based on the casting parameters, a predetermined casting simulation is executed to obtain a porosity for each divided region, the cavity volume ratio data, and the simulation. And result verification means and porosity data obtained by Shon means to verify for each divided region to evaluate the validity of the simulation results, characterized in that it comprises a.

  The casting internal defect inspection support method of the present invention receives cross-sectional images of a plurality of cross sections of the cast product formed by actually measuring a cast product to be inspected, and based on the tomographic images of the plurality of cross sections, An actual measurement model forming step for forming a three-dimensional shape model, a defect identification step for identifying a portion corresponding to a cavity in the casting as a hollow model from the three-dimensional shape model formed in the actual measurement model formation step, and the defect identification A cavity volume ratio calculating step of providing a divided area in the cavity model identified in the process and calculating a cavity volume ratio for each of the divided areas.

  Further, the casting internal defect inspection support method of the present invention receives a cross-sectional image of a plurality of cross sections of the cast product formed by actually measuring a cast product to be inspected, and based on the tomographic images of the plurality of cross sections, the casting An actual measurement model forming step for forming a three-dimensional shape model of the product, a defect identification step for identifying a portion corresponding to a cavity in the cast product as a hollow model from the three-dimensional shape model formed in the actual measurement model forming step, A cavity volume ratio calculating step for calculating a cavity volume ratio for each of the divided areas by providing a partition area in the cavity model identified in the defect identification process, and shape information of the cast product and a casting result of the cast article or correction. Based on the casting parameters, a predetermined casting simulation is executed to obtain a porosity for each divided region, the cavity volume ratio data, and the simulation. And results verification step of the porosity data obtained by Shon process to verify for each divided region to evaluate the validity of the simulation results, characterized in that it comprises a.

  First, a first embodiment of the present invention (hereinafter referred to as Embodiment 1) will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating a schematic configuration of a cast product inspection support system according to the first embodiment. As shown in FIG. 1, the system includes an X-ray CT scanner 10, an examination support device 20, a display device 60, and an input device 62.

  The X-ray CT scanner 10 is an apparatus for taking a CT tomographic image by scanning a casting with X-rays.

  The inspection support apparatus 20 is an apparatus that creates information that assists the inspection of internal defects of cast products based on CT tomographic images and provides the information to the user. The measurement model forming unit (measured model forming unit, hereinafter, the unit is referred to as a unit). The same applies to the others.) 22, a defect identification unit 24, a cavity volume ratio calculation unit 26, and a drawing unit 28. For example, the inspection support apparatus 20 applies processing contents such as an actual measurement model forming unit 22, a defect identifying unit 24, a cavity volume ratio calculating unit 26, and a drawing unit 28 described below to a general-purpose computer system such as a personal computer or a workstation. This can be realized by executing the described program.

  Among these, the actual measurement model forming unit 22 forms a three-dimensional shape model of a cast product from the tomographic image group input from the X-ray CT scanner 10. Here, a polygon surface model in which the surface of the cast product is represented by a polygon (polygonal surface element) is created as a three-dimensional shape model. As an algorithm for creating a polygon model from such a group of tomographic images, for example, a conventionally known algorithm such as a marching cube method can be used. Since the X-ray absorption rate differs greatly between air and cast metal (for example, aluminum or cast iron), a large difference appears between the pixel values (CT values) in the CT tomographic image. Therefore, when a polygon model is created from a CT tomographic image group by a technique such as a marching cube method, the boundary surface between the cast metal portion and air is converted to polygon data. That is, in the polygon model formed by the actual measurement model forming unit 22, not only the boundary surface between the cast product and the outside, but also the inner surface of the hollow portion due to internal defects such as a cast hole inside the cast product is expressed.

  The defect identifying unit 24 identifies a portion corresponding to an internal defect in the cast product from the three-dimensional shape model formed by the actual measurement model forming unit 22. Here, a polygon group corresponding to the boundary surface (referred to as the outer surface) with the outside (outside air) of the casting is extracted from the polygon surface model, and the remaining polygon group is recognized as the boundary surface with the cavity portion of the internal defect. To do.

  The cavity volume ratio calculation unit 26 calculates the volume ratio for each divided region of the simulation for the cavity (cast hole) that is the internal defect identified by the defect identification unit 24 (the calculation method will be described later).

  The drawing unit 28 forms a display image of a three-dimensional shape model formed by the actual measurement model forming unit 22 according to a user's request, or a display image in which the volume ratio distribution of internal defects for each divided region is easily colored and highlighted. It is a means to generate.

  A storage unit 30 such as a hard disk drive provided in the inspection support apparatus 20 is captured by an X-ray CT scanner and is formed by a measured model forming unit 22 and a product shape model identified by a defect identifying unit 24. 34, the cavity shape model 36, the cavity volume ratio distribution data 38 calculated by the cavity volume ratio calculator 26, and the like are stored.

  The display device 60 is a device that displays a display screen generated by the inspection support device 20, and displays, for example, a three-dimensional image of a cast product generated by the drawing unit 28.

  The input device 62 is a device that receives input of data and instructions to the examination support device 20 such as a keyboard and a pointing device.

  Next, with reference to FIG. 2, the procedure of the internal defect inspection support process of the cast product by this system will be described.

  First, in this system, the X-ray CT apparatus 10 scans a cross section at a predetermined interval (for example, 1 mm, etc., which depends on the accuracy of the three-dimensional shape model to be created) of the casting to be inspected. A tomographic image is created (S10). The data of the tomographic image of each cross section obtained as a result is input to the examination support apparatus 20. The actual measurement model forming unit 22 of the inspection support apparatus 20 forms a three-dimensional shape actual measurement model (hereinafter referred to as a polygon surface model) of a cast product to be inspected from the tomographic image group using an algorithm such as a marching cube method. (S12). Next, the defect identifying unit 24 identifies a portion corresponding to an internal defect in the casting from the polygon surface model, and separates it into a cavity shape model (hereinafter referred to as a cast hole model) and a product shape model (S14). ).

  Here, a polygon group corresponding to the boundary surface (referred to as the outer surface) with the outside (outside air) of the casting is extracted from the polygon surface model, and the remaining polygon group is recognized as the boundary surface with the cavity portion of the internal defect. To do. Here, in order to recognize the outer surface, a polygon surface model is first displayed on the display device 60, and the user is requested to designate a polygon corresponding to the outer surface of the cast product on the display. Starting from the polygon designated in this way, a polygon connected to a polygon already recognized as the outer surface (that is, sharing a side) is searched for and newly recognized as the outer surface. That is, the storage unit 30 stores that the polygon obtained by searching corresponds to the outer surface. If this process is repeated until there are no more polygons recognized as the outer surface, all the polygons corresponding to the outer surface of the cast product can be extracted, and a surface model can be generated. The obtained surface is stored as a product shape model 32 in the storage unit 30.

  In the case of a cast product, the boundary surface that is not the outer surface (that is, the inner surface of the cast product) may be considered as an internal defect. Therefore, after all the polygons on the outer surface are extracted, the polygons for which information indicating the outer surface is not stored can be considered as polygons surrounding a cavity (hereinafter referred to as a cast hole) that is an internal defect. Therefore, after extracting all the polygons connected to the polygon specified by the user, it is possible to identify each remaining polygon without being extracted as a polygon corresponding to the cast hole of the cast product, thereby generating a cast hole model. . The obtained cast hole model is stored in the storage unit 40 as the cavity shape model 36.

  Next, the obtained cavity shape model 36 is aligned with predetermined simulation data (for example, CAD data), and a divided region is set (S16). The size of the divided region is not particularly limited, and may be, for example, 2.5 mm × 2.5 mm × 2.5 mm. The divided areas are set in this way, and the volume ratio of the cast hole occupying each divided area is calculated by the following method (S18).

  In general, if the volume to be obtained is a volume of a closed space model composed of a surface mesh, it can be easily obtained by geometric calculation. However, as for the relationship between the cast hole model and the simulation divided region, for example, as shown in FIG. 3, one cast hole model exists over a large number of divided regions. That is, in the divided region A, the portion b shown by diagonal lines is a cast hole (that is, a cavity), but the portion a is a metal portion. That is, the volume ratio V (%) of the cast hole in the divided region A can be expressed as V (%) = Vb / (Va + Vb) × 100. However, the void portion b is not a closed space, and the divisional area is in a positional relationship where the triangular surface mesh intersects, and it is difficult to obtain the volume Vb of the void portion b by the conventional calculation method. .

  In the present invention, when simulating the course of a coincidence phenomenon in this calculation, a Monte Carlo method is used in which a numerical calculation is performed using random numbers to obtain an approximate solution of the problem. That is, this is a method in which a point P is plotted three-dimensionally in a divided area using random numbers, and it is determined whether the point P is inside or outside the casting hole in the divided area. A number of points are plotted in the divided area, and whether each point is inside or outside the cast hole is determined. The ratio of the number of points determined to be in the cast hole to the total number of plotted points is determined in the divided area. The volume ratio of the cast hole. Therefore, the larger the number of points plotted in the region, the higher the accuracy of the obtained void volume ratio, but it can be set to an appropriate score in consideration of the time required for calculation. For example, about 1000 points may be set for each divided region. In addition, the plot position of each point does not necessarily need to be random, and may be plotted at an appropriate pitch.

  Next, a determination method for determining whether a point plotted in a certain divided region is inside or outside the cast hole will be described with reference to FIG.

  FIG. 4 is a schematic diagram showing a certain divided region A two-dimensionally for ease of explanation. The divided area A includes a part of the cast hole model B surrounded by the mesh surface C. Here, a method for determining whether or not the plotted point P is inside the cast hole model B (that is, the b side) (a side) will be described.

  In this method, the nearest point P ′ that is the shortest distance on the mesh surface C is searched from the plotted point P, and the relationship between the vector PP ′ and the normal vector n of the polygon including the nearest point P ′ This is a method of making a determination.

The closest point P ′ is one of three types shown in FIG. 5 depending on the positional relationship between the point P and the polygon.
That is, (a) when found on the polygon, (b) when located on the ridgeline of the polygon, and (c) when located on the vertex of the polygon. Therefore, the search order of the nearest point P ′ is to first search on all polygons in the divided area not including the vertex and the edge line, and then search on edge lines associated with all the polygons in the divided area. Subsequently, search is performed on vertices associated with all the polygons in the divided area. In this way, the surface of the polygon, the ridgeline, and the vertex are searched in this order to find the point having the shortest distance as the closest point P ′, and the vector PP ′ is determined.

  When the nearest point P ′ is on the surface of the polygon, the inner product of the vector PP ′ and the normal vector n of the polygon including the nearest point P ′ is obtained. Since the normal vector n is always in the direction from the metal side to the outside (in this case, the direction toward the inside of the cast hole), if the inner product value obtained is negative (minus), the point P is the cast model. If it is inside B and the value of the inner product is positive (plus), it is determined that the point P is outside the cast hole model B. When the nearest point P ′ is on the ridgeline or vertex of the polygon, the inner product of the inner product in the polygon group sharing the nearest point P ′ (for example, x, y, z in FIG. 5c). The inside / outside determination of the point P is performed with the largest value.

  Further, in the case of a large casting hole model that completely includes the divided area A as in the casting hole model B shown in FIG. 6, the volume ratio of the casting hole in the divided area A is 100%. However, in the above method, since the calculation target is one divided region, the vector PP ′ cannot be determined in the divided region A. Therefore, an erroneous determination is made, and as a result, 0% is output. Become. Therefore, in the case of a cast hole model B as shown in FIG. 6, the calculation range of the cast hole volume ratio is expanded to 26 divided areas adjacent to the divided area A for calculation. If necessary, a wider range is calculated as a calculation target.

  The above operation steps are performed for all the divided areas, and the volume ratio distribution data 38 of the cast hole is created and stored in the storage unit 30. Here, S10 and S12 are actual measurement model formation processes, S14 is a defect identification process, and S16 and S18 are cavity volume ratio calculation processes.

  As described above, according to the system of the present embodiment, a three-dimensional shape model is formed from a tomographic image of a cast product, an internal defect is identified from the three-dimensional shape model as a void model, and the volume ratio is divided into regions. It is possible to grasp quantitatively every time.

  Next, a second embodiment (referred to as a second embodiment) of the present invention will be described with reference to FIGS. FIG. 7 is a diagram showing a system configuration of the second embodiment. Components corresponding to the components of the first embodiment shown in FIG. 1 are denoted by the same reference numerals as those in FIG. To do.

  The system of Embodiment 2 aims at improving the accuracy of casting simulation for casting process design in a casting department or the like. In the second embodiment, in addition to the system configuration of the first embodiment, a casting simulation unit 60 and a result verification unit 62 are provided in the inspection support apparatus 20.

  The casting simulation unit 50 is a means for performing a simulation calculation for obtaining the occurrence position, shape, size, etc. of a casting defect, and the design shape and casting parameters (for example, the temperature of the molten metal, the injection location, etc.) ), A model for analysis is created, and a known analysis operation such as solidification analysis is performed on this model. As the simulation algorithm, various conventional algorithms such as Japanese Patent Application Laid-Open No. 2001-287023 can be used.

  In the storage unit 40 such as a hard disk drive provided in the inspection support device 20, the design shape data 42 of the cast product, the casting parameters 44 when casting the cast product, and the void ratio which is a simulation result by the casting simulation unit 50. Distribution data 46 and the like are stored.

  Next, with reference to FIG. 8, a procedure of processing according to the second embodiment will be described. Note that description of the same processing as in the first embodiment is omitted.

  In this system, first, similarly to the first embodiment, X-ray CT measurement is performed on a plurality of cast products, and the volume ratio of the casting cavity is calculated for each divided region to create the cavity volume ratio distribution data 38 (S20).

  Next, the user activates the casting simulation unit 50 and sets the design shape data 42 to be simulated and various casting parameters 44 as casting conditions for the simulation unit 50. The casting simulation unit 50 creates an analysis model in accordance with these settings, executes a predetermined casting simulation, calculates the void ratio (corresponding to the cast hole volume ratio) for each divided region, and generates the porosity distribution data 46. Create (S22). The obtained porosity distribution data 46 is stored in the storage unit 40.

  In the second embodiment, in the result verification step (S24, S26), the previously obtained void volume distribution data 38 and the porosity distribution data 46 as a simulation result are compared and verified. Here, the porosity for each divided area in the porosity distribution data 46 is compared with the volume ratio in each divided area of the casting hole in the casting volume distribution data 38, and a simulation is performed based on the casting volume ratio distribution data 38. Is evaluated for each divided region.

  For example, when the difference between the void volume ratio and the void ratio in a certain divided area is within the allowable range, the area is evaluated as +1 point, and conversely, when the deviation is outside the allowable range, the area is 0 point. And evaluate. Alternatively, it is also preferable that the allowable range is further ranked according to the magnitude of the difference (for example, if the difference between the two is less than 5%, +5 points, 5-10% is +3 points, 10% or more is +1 point, etc.). In addition, it is also desirable to evaluate it as -1 point etc., when a void rate is recognized although a void volume is 0%, or the contrary.

  By assigning evaluation points for all the divided areas as in these examples and tabulating, simulation results (porosity distribution data 46) under certain setting conditions are quantitatively calculated based on the void volume distribution data 38 (for example, It is possible to evaluate the accuracy of the casting volume ratio distribution data as 100). Here, it is also preferable that the evaluation points of each region are weighted and evaluated based on the high probability of defect appearance, the importance of the occurrence site, and the like.

  If the evaluation score of the simulation result is outside the allowable range of the preset evaluation score, the design shape data and casting parameters are adjusted and changed in step S30, and the process returns to S22 to return the gap for each divided region. The ratio is obtained, and the process is repeated until the evaluation score of the simulation result falls within the preset allowable range by comparing with the cast volume ratio again.

  As described above, in the system of the second embodiment, since the validity of the simulation can be quantitatively evaluated and grasped, the design and casting parameters can be refined and the effectiveness can be verified with a smooth flow. Accuracy can be dramatically improved in a short time.

  In the second embodiment, since the simulation result can be quantitatively evaluated, the evaluation score of the simulation result shows an extreme value, or when the casting condition does not easily fall within the allowable range even when variously changed. It is also possible to make a determination that the simulation algorithm of the casting simulation unit 50 needs to be improved. Here, S22 is a simulation process, and S24, S26, and S30 are result verification processes.

  According to the present invention, it is possible to quantitatively grasp the volume ratio as well as the generation site and size of a cast hole of a cast product. Therefore, it can be suitably applied to the quality judgment of cast parts in automobile manufacturers and cast parts manufacturers, and greatly contributes to the improvement of product quality.

  In addition, since the effectiveness of simulation can be quantitatively evaluated by comparing measured data with simulation results, it is possible to further improve simulation accuracy and greatly shorten the examination period from trial production to mass production. be able to.

It is a figure which shows the system configuration | structure of Embodiment 1 of this invention. 3 is a flowchart illustrating a processing procedure of the system according to the first embodiment. It is explanatory drawing which showed the relationship between a cast hole model and a division area in two dimensions. It is explanatory drawing explaining the determination method which discriminate | determines the presence position with respect to the cast hole of the plotted point. It is a figure which shows typically the relationship between the nearest point P 'and a polygon. (A) on polygon, (b) on ridgeline, (c) on vertex It is a schematic diagram which shows an example of the cast hole model containing the division | segmentation area | region A. It is a figure which shows the system configuration | structure of Embodiment 2. FIG. 10 is a flowchart illustrating a processing procedure according to the second embodiment.

Explanation of symbols

A: Divided area B: Cast hole model C: Mesh surface of the cast hole model P: Plot point d: PP 'vector n: Normal vector

Claims (5)

Measured model forming means for receiving cross-sectional images of a plurality of cross sections of the cast product formed by actually measuring a cast product to be inspected, and forming a three-dimensional shape model of the cast product based on the tomographic images of the cross sections When,
Defect identifying means for identifying a portion corresponding to a cavity in the casting from the three-dimensional shape model formed by the measured model forming means as a cavity model;
A cavity volume ratio calculating means for providing a divided area in the cavity model identified by the defect identifying means and calculating a cavity volume ratio for each of the divided areas;
A casting internal defect inspection support device characterized by comprising: The actual measurement model forming means forms a surface model of the casting as the three-dimensional shape model,
The defect identifying means identifies a surface element group constituting the outer surface of the cast product in the surface model, and identifies a surface element other than the surface elements constituting the outer surface as a surface element surrounding the cavity. Identify the part corresponding to the cavity,
The volume ratio calculating means plots a large number of points for each divided region, determines a point existing in the cavity in the divided region from the large number of points, and determines the cavity for the total number of points plotted in the divided region. The casting internal defect inspection support device according to claim 1, wherein the ratio of the number of points determined to be present inside is calculated as a cavity volume ratio. Measured model forming means for receiving cross-sectional images of a plurality of cross sections of the cast product formed by actually measuring a cast product to be inspected, and forming a three-dimensional shape model of the cast product based on the tomographic images of the cross sections When,
Defect identifying means for identifying a portion corresponding to a cavity in the casting from the three-dimensional shape model formed by the measured model forming means as a cavity model;
A cavity volume ratio calculating means for providing a divided area in the cavity model identified by the defect identifying means and calculating a cavity volume ratio for each of the divided areas;
A casting simulation means for performing a predetermined casting simulation based on the shape information of the cast product and the casting performance of the cast product or a corrected casting parameter to obtain a porosity for each divided region;
Result verification means for verifying the void volume data and the porosity data obtained by the simulation means for each divided region and evaluating the validity of the simulation results;
A casting internal defect inspection support device characterized by comprising: An actual measurement model forming step of receiving cross-sectional images of a plurality of cross sections of the cast product formed by actually measuring a cast product to be inspected, and forming a three-dimensional shape model of the cast product based on the tomographic images of the cross sections When,
A defect identification step for identifying a portion corresponding to a cavity in the casting as a cavity model from the three-dimensional shape model formed in the actual measurement model formation step;
A cavity volume ratio calculating step for providing a divided area in the cavity model identified in the defect identification process and calculating a cavity volume ratio for each divided area;
A casting internal defect inspection support method characterized by comprising: An actual measurement model forming step of receiving cross-sectional images of a plurality of cross sections of the cast product formed by actually measuring a cast product to be inspected, and forming a three-dimensional shape model of the cast product based on the tomographic images of the cross sections When,
A defect identification step for identifying a portion corresponding to a cavity in the casting as a cavity model from the three-dimensional shape model formed in the actual measurement model formation step;
A cavity volume ratio calculating step for providing a divided area in the cavity model identified in the defect identification process and calculating a cavity volume ratio for each divided area;
A casting simulation step of performing a predetermined casting simulation based on the shape information of the cast product and the casting performance of the cast product or a corrected casting parameter to obtain a porosity for each divided region;
A result verification step of verifying the void volume data and the porosity data obtained by the simulation step for each divided region and evaluating the validity of the simulation result;
A casting internal defect inspection support method characterized by comprising:

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